The present invention relates generally to systems and methods for removing organics from water, and more particularly to an improved packed column and method for air stripping volatile organic compounds from groundwater.
Existing methods for removing and/or destroying organic compounds from water include incineration, liquid phase adsorption, chemical oxidation, biological oxidation, steam stripping and air stripping. Volatile organic compounds may contaminate groundwater from sources such as industrial spills, leaking underground storage tanks and improperly constructed surface impoundments and landfills. Removal of volatile organic compounds from groundwater using any of the technologies just mentioned may be effective, but additional treatment for destruction of the contaminants may be necessary since adsorption and stripping only transfer and concentrate the organics. For concentrations of but a few ppm, incineration and chemical or biological oxidation may be prohibitively expensive. Air stripping may generally be the less costly and preferred process for many groundwater decontamination applications.
The invention solves or substantially reduces in critical importance certain shortcomings in the prior art by providing a cascade crossflow air stripping system and method wherein the path along which air is flowed is disconnected at intervals from regions through which the liquid flows. The system operates in a generally countercurrent manner with liquid flowing downwardly by gravity, but the air is deflected at regular intervals by baffles causing the air flow to cross the liquid flow direction generally perpendicularly several times. Proper baffle spacing may produce marked reduction in air velocity and smaller pressure drop as compared to conventional countercurrent operation.
It is therefore a principal object of the invention to provide system and method for removing organics from water.
It is a further object of the invention to provide system and method for removing volatile organic compounds from groundwater.
These and other objects of the invention will become apparent as a detailed description or representative embodiments proceeds.